When laminating over foam I think the main thing is to make sure your foam is strong enough to withstand the force of the vacuum. I have access to some sturdy enough foam. But I will def take your point about sharp corners and not design any harsh edges into the shape.
I'll likely be using braided sleeves and possibly MTI infusion hose as it can be laid straight onto the part.
Proof of concept, yes but more in the sense that I'll like the barrel to actually be useable. Anyways, I'm drifting thread this seriously now. But thanks for the pointers.